• The Korean Journal of Physiology and Pharmacology
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• 제21권5호
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• pp.509-518
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• 2017

Glioblastoma multiforme (GBM) is the most common primary intracranial tumor in adults and has poor prognosis. The GBM-specific tumor microenvironment (TME) plays a crucial role in tumor progression, immune escape, local invasion, and metastasis of GBM. Here, we demonstrate that hypoxia, reactive oxygen species (ROS), and differential concentration of glucose influence the expression of cytokines and chemokines, such as IL-6, IL-8, and IP-10, in human glial cell lines. Treatment with cobalt chloride ($CoCl_2$) and hydrogen peroxide ($H_2O_2$) significantly increased the expression levels of IL-6, IL-8, and IP-10 in a dose-dependent manner in CRT-MG and U251-MG astroglioma cells, but not in microglia cells. However, we found strikingly different patterns of expression of cytokines and chemokines between $H_2O_2$-treated CRT-MG cells cultured in low- and high-glucose medium. These results suggest that astroglioma and microglia cells exhibit distinct patterns of cytokine and chemokine expression in response to $CoCl_2$ and $H_2O_2$ treatment, and different concentrations of glucose influence this expression under either hypoxic or oxidant-enriched conditions.

• Preventive Nutrition and Food Science
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• 제21권4호
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• pp.297-309
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• 2016

Around the world, fermentation of foods has been adopted over many generations, primarily due to their commercial significance with enriched flavors and high-profile nutrients. The increasing application of fermented foods is further promoted by recent evidence on their health benefits, beyond the traditionally recognized effects on the digestive system. With recent advances in the understanding of gut-brain interactions, there have also been reports suggesting the fermented food's efficacy, particularly for cognitive function improvements. These results are strengthened by the proposed biological effects of fermented foods, including neuroprotection against neurotoxicity and reactive oxygen species. This paper reviews the beneficial health effects of fermented foods with particular emphasis on cognitive enhancement and neuroprotective effects. With an extensive review of fermented foods and their potential cognitive benefits, this paper may promote commercially feasible applications of fermented foods as natural remedies to cognitive problems.

• Corrosion Science and Technology
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• 제17권4호
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• pp.147-153
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• 2018

Copper is used in various applications in environments favoring and enabling formation of biofilms by naturally occurring microbes. Copper is also the chosen corrosion barrier for nuclear waste in Finland. The copper canisters should have lifetimes of 100,000 years. Copper is commonly considered to be resistant to corrosion in oxygen-free water. This is an important argument for using copper as a corrosion protection in the planned canisters for spent nuclear-fuel encapsulation. However, microbial biofilm formation on metal surfaces can increase corrosion in various conditions and provide conditions where corrosion would not otherwise occur. Microbes can alter pH and redox potential, excrete corrosion-inducing metabolites, directly or indirectly reduce or oxidize the corrosion products, and form biofilms that create corrosive microenvironments. Microbial metabolites are known to initiate, facilitate, or accelerate general or localized corrosion, galvanic corrosion, and intergranular corrosion, as well as enable stress-corrosion cracking. Sulfate-reducing bacteria (SRB) are present in the repository environment. Sulfide is known to be a corrosive agent for copper. Here we show results from corrosion of copper in anoxic simulated ground water in the presence of SRB enriched from the planned disposal site.

• Fisheries and Aquatic Sciences
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• 제1권2호
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• pp.159-167
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• 1998

The environmental characteristics in shellfish farms were investigated in the western part of Jinhae Bay, 1996. During summer, anoxia and high nutrient concentrations were found in the bottom waters of shellfish farms. The concentrations of particulate organic species in seawaters were enriched, showing an average 57.44 uM for POC, an average 5.45 uM for PON, and an average 0.42uM for PP. The sediments environment in the farms was very polluted. The concentrations of COD and AVS were more than 20 mg/g.dry and 0.5 mg/g.dry, respectively. The total sedimentation rate was high as an average $7.81g/m^2/day$ with organic matter contents of $26\%$. Oxygen consumption rate was similar to polluted area as an average of $439mg/m^2/day$. Nutrient release rates were an average of $8.25mg/m^2/day$ for nitrogen and an average of $1.38mg/m^2/day$ for phosphorous. The cluster analysis through environmental data in summer indicated that DO, nutrient in the bottom water, and AVS in the sediment were important factors to characterize the polluted environmental site.

• 한국어병학회지
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• 제25권3호
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• pp.199-210
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• 2012

It can be hypothesized that dietary fatty acids can modulate immune responses in fish by inducing apoptosis of immune cells since dietary polyunsaturated fatty acid (PUFA) increase apoptosis by oxygen radicals generated by peroxidation. Thus we examined the effects of deferent dietary lipid sources such as squid liver oil (FO), linseed oil (LO) and soybean oil (SO) on oxidation (Cytochrome C oxidase; COS), apoptosis (TNF-${\alpha}$ Scinderin like) and immune (IL-$1{\beta}$ and NKEF) gene expression in the main immune organ (head kidney) in olive flounder (Paralichthys olivaceus) by Q-PCR analysis after feeding diets containing each oil (5%) for 15 weeks. Linseed oil and soybean oil were chosen to compare n-3 or n-6 enriched vegetable oils, respectively. Consequently, COS, TNF-${\alpha}$ and Scinderin like gene expression was increased in SO group, indicating the induction of oxidation and apoptosis. Meanwhile, no significant difference was found in immune gene expression. In conclusion vegetable oils containing n-3 PUFA like linseed oil seems to be more suitable lipid source than soybean oil for replacement of fish oil in flounder since n-6 PUFA in SO leads to activation of apoptosis pathways within the cellular damage in head kidney.

• 한국식품과학회지
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• 제46권5호
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• pp.531-537
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• 2014

십자화과 채소인 콜라비 및 무에는 glucosinolate 성분이 함유되어 있으며, 특히 새싹 채소의 경우 성숙한 채소보다 glucosinolate의 함량이 더 높은 것으로 알려져 있다. 이와 같은 이유로 최근 새싹채소에 대한 관심은 높으나, 아직 새싹채소에 대한 연구는 미비한 편이다. 따라서 본 연구에서는 십자화과 채소인 콜라비 새싹 추출물(KSE) 및 무순 추출물(RSE)의 total carotenoid 및 glucosinolate의 함량을 분석하였고 이들 추출물의 항산화 및 anti-adipogenic 활성을 평가하였다. KSE의 total carotenoid 및 glucosinolate 함량은 각각 $39.50{\pm}0.67$ 및 $2.65{\pm}0.02mg/g$이며, RSE의 total carotenoid 및 glucosinolate 함량은 각각 $76.73{\pm}2.75$ 및 $8.13{\pm}0.54mg/g$으로 KSE보다 높았다. 다양한 항산화 평가 모델(DPPH, ABTS, FRAP, reducing power)을 통하여 항산화 활성을 측정한 결과, KSE 및 RSE는 농도 의존적으로 항산화 활성이 증가하는 경향을 나타내었다. 또한, 지방세포의 분화과정에서 KSE 및 RSE의 처리는 지방세포의 지방축적 및 ROS 생성을 억제하였으며, KSE 및 RSE의 주요 성분으로 알려진 ${\beta}$-carotene, glucoraphanin 및 glucoraphenin의 처리는 지방 축적 억제 및 ROS 생성 저감 활성을 나타내었다. 이상의 결과로부터, ${\beta}$-carotene, glucoraphanin 및 glucoraphenin이 풍부한 RSE 및 KSE는 항산화 활성 및 지방세포 분화억제 효능을 갖으며, 천연물 유래 항비만 소재로서 활용 가능성이 높은 것으로 기대된다.

• Journal of the korean society of oceanography
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• 제34권2호
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• pp.122-131
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• 1999

This study examined the relationship between the sediment pollution and the occurrence of polychaetes in a heavily polluted saltwater lake, Lake Shihwa on the west coast of Korea, separated from the sea by a dike in 1994. The species composition of polychaete assemblage was compared with that found off the lake in Kyeonggi Bay. Environmental variables investigated both in and off the lake were the grain size distribution, chemical oxygen demand(COD) and metal concentrations (Al, Fe, Mn, V, Co, As, Pb, Cr and Cu) in the sediment. We sampled sediments at 10 stations in the lake and 25 stations in Kyeonggi Bay using a modified van Veen grab. The levels of COD, chromium, and copper in sediments were much higher in Lake Shihwa than in Kyeonggi Bay. Differences in the species composition were found along the pollution gradient. An azoic zone was observed in the most heavily polluted area at the upper reach of the lake and the Polydora ligni zone in the center of the lake. Bottom fauna were diverse in Kyeonggi Bay; however, Heteromastus filiformis predominated in the organically enriched sediment. The density of dominant species differed along the pollution gradient. The highest density or H. filiformis was round at the COD level or around 5.8 mg/g. The COD level in the sediment where P. ligni predominated was tow-fold higher than that where H. filiformis occurred in large numbers. The chromium and copper contents at which P. ligni showed a maximum abundance were 120 mg/kg and 127 mg/kg, respectively. The density of H. filiformis was highest at concentrations of 56 mg/kg chromium and 13 mg/kg copper.

• Ocean Science Journal
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• 제42권1호
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• pp.9-17
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• 2007

The summer distributions of planktonic microbial communities (heterotrophic and phtosynthetic bacteria, phtosynthetic and heterotrophic nanoflagellates, ciliate plankton, and microphytoplankton) were compared between inner and outer areas of Lake Sihwa, divided by an artificial breakwater, located on the western coast of Korea, in September 2003. The semi-enclosed, inner area was characterized by hyposaline surface water (<17 psu), and by low concentrations of dissolved oxygen (avg. $0.4\;mg\;L^{-1}$) and high concentrations of inorganic nutrients (nitrogenous nutrients $>36\;{\mu}M$, phosphate $>4\;{\mu}M$) in the bottom layer. Higher densities of heterotrophic bacteria and nanoflagellates also occurred in the inner area than did in the outer area, while microphytoplankton (mainly diatoms) occurred abundantly in the outer area. A tiny tintinnid ciliate, Tintinnopsis nana, bloomed into more than $10^6\;cells\;L^{-1}$ at the surface layer of the inner area, while its abundance was much lower ($10^3-10^4\;cells\;L^{-1}$) in the outer area of the breakwater. Ciliate abundance was highly correlated with heterotrophic bacteria (r = 0.886, p < 0.001) and heterotrophic flagellates (r = 0.962, p < 0.001), indicating that rich food availability may have led to the T. nana bloom. These results suggest that the breakwater causes the eutrophic environment in artificial lakes with limited flushing of enriched water and develops into abundant bacteria, nanoflagellates, and ciliates.

• Corrosion Science and Technology
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• 제12권6호
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• pp.274-279
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• 2013

Flow accelerated corrosion (FAC) of the carbon steel piping in nuclear power plants (NPPs) has been major issue in nuclear industry. During the FAC, a protective oxide layer on carbon steel dissolves into flowing water leading to a thinning of the oxide layer and accelerating corrosion of base material. As a result, severe failures may occur in the piping and equipment of NPPs. Effect of alloying elements on FAC of pipe materials was studied with rotating cylinder FAC test facility at $150^{\circ}C$ and at flow velocity of 4m/s. The facility is equipped with on line monitoring of pH, conductivity, dissolved oxygen(DO) and temperature. Test solution was the demineralized water, and DO concentration was less than 1 ppb. Surface appearance of A 106 Gr. B which is used widely in secondary pipe in NPPs showed orange peel appearance, typical appearance of FAC. The materials with Cr content higher than 0.17wt.% showed pit. The pit is thought to early degradation mode of FAC. The corrosion product within the pit was enriched with Cr, Mo, Cu, Ni and S. But S was not detected in SA336 F22V with 2.25wt.% Cr. The enrichment of Cr and Mo seemed to be related with low, solubility of Cr and Mo compared to Fe. Measured FAC rate was compared with Ducreaux's relationship and showed slightly lower FAC rate than Ducreaux's relationship.

• 한국물환경학회지
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• 제36권1호
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• pp.55-68
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• 2020

Because of the intensified environmental problems such as climate change and resource depletion, sewage treatment technology focused on energy management has recently attracted attention. The conversion of primary sludge from the primary sedimentation tank and excessive sludge from the secondary sedimentation tank into biogas is the key to energy-positive sewage treatment. In particular, the primary sedimentation tanks recover enriched biodegradable organic matter and anaerobic digestion process produces methane from the organic wastes for energy production. Such technologies for minimizing oxygen demand are leading the innovation regarding sewage treatment plants. However, sewage treatment facilities in Korea lack core technology and operational know-how. Actually, the energy potential of sewage is higher than sewage treatment energy consumption in the sewage treatment, but current processes are not adequately efficient in energy recovery. To improve this, it is possible to apply chemically enhanced primary treatment (CEPT), high-rate activated sludge (HRAS), and anaerobic membrane bioreactor (AnMBR) to the primary sedimentation tank. To maximize the methane production of sewage treatment plants, organic wastes such as food waste and livestock manure can be digested. Additionally, mechanical pretreatment, thermal hydrolysis, and chemical pretreatment would enhance the methane conversion of organic waste. Power generation systems based on internal combustion engines are susceptible to heat source losses, requiring breakthrough energy conversion systems such as fuel cells. To realize the energy positive sewage treatment plant, primary organic matter recovery from sewage, biogas pretreatment, and co-digestion should be optimized in the energy management system based on the knowledge-based operation.